This invention relates to a storage case or box suitable for loading or storing, for example, a cartridge or cassette of film, magnetic tape, etc.
Conventionally, as this type of storage case there is known the one wherein a storing body having a front side plate and right and left side plates, a covering for covering an upwardly directed opening of the storing body, and a rear side plate commonly connected to the storing body and covering are integrally formed of synthetic resin material; and the rear side plate is made to function as a hinge to make possible the opening and closing operation of the covering. In such type of storage case, in order to prevent the covering from being opened, when having been closed, due to a restoring force of the rear side plate, there is provided an engaging mechanism wherein either one of the mutually overlapping front side plates of the storing body and covering is provided with an engagement projection and the other with an engagement depression engageable with this projection. Since, however, in this engaging stopper mechanism, the engaging function is performed when the engagement projection is inserted into the engagement depression, it is not reliably performed unless both front side plates of the storing body and covering are closely approached to each other, and even when the covering is closed, application of a small external force causes the covering to be opened soon. Since, however, a dimensional tolerance for permitting both front side plates to overlap on each other should be provided and dimensional errors upon manufacture are produced, it often happens, actually, that both front side plates fail to be mutually closely approached to a required extent. This poses the above-mentioned problems.